/Engine/Source/Editor/Sequencer/Public/ISequencer.h
Gets the currently selected key areas. If bIncludeSelectedKeys is true it will include key areas for selected keys, if not will only include key areas for selected display nodes
void GetSelectedKeyAreas ( [TArray](API\Runtime\Core\Containers\TArray)< const [IKeyArea](API\Editor\Sequencer\IKeyArea) * > & OutSelectedKeyAreas, bool bIncludeSelectedKeys )